The present invention relates to vehicle bumper systems, and more particularly relates to a bumper system having an integrated energy absorber and beam, and also relates to novel beam constructions such as are shaped for engagement with mating energy absorbers.
Bumper systems using integrated energy absorber and bumper beam arrangements are desired to improve assembly of bumper systems to vehicles, to minimize the number and types of mechanical fasteners overall, and to simplify tooling. In particular, it is desirable to provide a design where the beam and energy absorber can be assembled off-line of the main vehicle assembly line into a unitary subassembly, and then manipulated as a unit for attachment to the vehicle. Also, it is desirable to attach fascia to the subassembly, and to integrate and attach other components to the subassembly, such as headlights, grilles, and other functional and ornamental components. At the same time, impact durability and enhanced energy absorption continue to be high priority items in bumper systems, and accordingly, any subassembly should preferably not detract from the same.
In addition to the above, many vehicle manufacturers and some insurance groups and government entities are pressing for improved crashworthiness of vehicles, and also for bumper systems that will provide for better pedestrian safety. Longer bumper strokes with lower initial energy absorption rates have the possibility of satisfying these desires, but this can result in energy absorbers that are physically larger in size than present bumper systems, and that are not easy to package and carry at a front of the vehicle. Thus, new integrated bumper systems are desired to deal with the conflicting functional and design requirements.
Improvements are also desired in rear bumper systems on vehicles. In particular, vehicle manufacturers are looking increasingly at energy absorbers for rear bumper systems that are not dissimilar in shape and function to energy absorbers for front bumper systems. However, the energy absorber of any such rear bumper system must be integrated into the bumper system such that it does not interfere with other functional and aesthetic requirements at a rear of the vehicle. For example, many rear bumper systems include a step, and/or are adapted to support a ball hitch for hauling a trailer.
Accordingly, bumper systems are desired solving the aforementioned problems and having the aforementioned advantages.
In one aspect of the present invention, a bumper system includes a tubular beam with front, rear, top, and bottom walls; the front and rear walls being reformed at ends of the tubular beam to form flattened end sections. The bumper system further includes an energy absorber having a rear surface with a recess mateably receiving the tubular beam, the recess including mating surfaces engaging a front of the flattened end sections. Vehicle mounts engage a rear of the flattened end sections, and fasteners secure the tubular beam and energy absorber to the mounts.
In another aspect of the present invention, a bumper system includes a beam having front, rear, top, and bottom walls defining a tubular center section and having end sections. The bumper system further includes a one-piece energy absorber having an absorber center section with a rear-facing recess mateably receiving the tubular center section and engaging portions of the front, top and bottom walls; and further having corner sections with an interior surface located proximate an outer end of the end sections of the beam. Mounts engage a rear of the end sections, with the interior surface of the corner sections being positioned to engage the outer end of the beam and to simultaneously engage an outer side surface of the mounts when the vehicle experiences a corner impact. Fasteners secure the tubular beam and energy absorber to the mounts.
In yet another aspect of the present invention, a bumper system for a vehicle having a passenger compartment includes a tubular bumper beam having a tubular bumper beam that includes a center section, end sections, and bent interconnecting sections that interconnect each end section with an end of the center section, with the center section being at least 25% of a length of the bumper beam and defining a longitudinal primary centerline, and the end sections being at least 15% of the length. The end sections each define a secondary centerline that extends parallel the primary centerline, with the secondary centerline being spaced horizontally from the primary centerline when in a vehicle-mounted position, and with the center section being located partially between the mounts and closer to the passenger compartment than the end sections. An energy absorber is provided that includes at least one recess shaped to receive a portion of the tubular bumper beam. Mounts are provided that are adapted for attachment to a vehicle and that are attached to the end sections.
An advantage of the present bumper systems is that some of the traditional front-end support structure can be simplified or eliminated. For example, the present inventive bumper system can include an energy absorber with portions that support the front-of-vehicle fascia in areas in front of the vehicle hood. This allows the front end support structure of the vehicle to be simplified, such as by eliminating fascia-supporting struts, by eliminating forwardly-extending flanges on the radiator cross support, by reducing the strength requirements on the radiator cross support and/or by eliminating or reducing strength requirements on a vehicle""s front end panel.